Printers printing printersTen years ago, open source 3D printers did not exist. You could buy a commercial machine for $20,000 and order the stock material from the manufacturer. Then, in 2007, the original patents on many of those machines expired.

In the spring of 2007, the first open source 3D printer came online at the University of Bath in the United Kingdom. This machine, composed largely of parts produced by a commercial printer, plus a few motors and circuit boards, was capable of manufacturing most of its own components. In 2008, the first fully self-replicating rapid prototyping machine, called the RepRap, was made of parts printed by another RepRap. It was open source hardware in the purest sense: Feed the open source design to a 3D printer and out pop the parts to assemble another.

Open source 3D printers are often developed in iterative cycles driven by their user communities. The quintessential example of an open source 3D printer company was MakerBot, although it veered away from its commitment to open source earlier this year. MakerBot has produced four distinct models over its four-year history, with a host of smaller upgrades incrementally introduced to various subsystems.

Often, these incremental improvements were designed by users. The new designs were then prototyped, shared, tested, and refined by the 3D printing community. Finally, they were incorporated into the next official MakerBot printer.

This process greatly reduced the cost and complexity of the machines. Today, $2,799 will purchase a Makerbot Replicator 2X, which outperforms the commercial machines of 2007 at a tenth of the price.

One of the benefits of open source software is that if something is broken or if you want to adjust functionality, you can implement those changes and share them. What makes 3D printing special is that it can be used to bring the open source philosophy to the physical world. It democratizes the means of production and puts design tools into the hands of anyone interested in building physical products. You can share, copy, and improve upon those designs. 3D printing makes iterative development possible for the physical world. And it all happens on your desk, in your apartment, or in your garage.

Tools of the tradeThe 3D printer itself is just a piece of equipment. To spit out a physical object, a 3D printer must be fed a detailed digital representation of that item, either created from scratch using 3D modeling software or scanned in using a 3D scanner.

Blender, originally designed for animators, is a great open source tool for building 3D designs. It particularly excels at organic shapes, such as faces and flowers. OpenSCAD, free software billed as "the programmer's 3D modeler," defines objects through the accretion of a handful of primitives (such as spheres and cubes) via Boolean logic into more complex objects, which are assembled in turn into larger objects. OpenSCAD excels at building easily tweaked shapes for more engineering-centered applications.